Incinerator ash removal apparatus

ABSTRACT

A valve and duct means are provided to extract ash-laden air from the combustion chamber of an incinerator and direct it to fly ash separators and a finer filter in order that small particles of ash may be separated from the air before the air is exhausted to atmosphere. An alternate path is provided to remove ash remaining in the combustion chamber after an incineration cycle is completed. Ash-laden air from the combustion chamber is directed to a cyclone separator to remove larger particles of ash from the air. The air is then sent through the fly ash separators and the finer filter in order to remove any remaining smaller particles of ash. The air is then returned to the combustion chamber where particles of ash remaining therein are stirred up by the returning air. Electrical circuitry is provided so that operation of the ash removal apparatus is substantially automatic. A protective circuit prevents operation of the ashremoval apparatus if the temperature in the combustion chamber is above a predetermined level.

United States Patent 91 1 Jan. 28, 1975 Eff [ lNClNERATOR ASH REMOVALAPPARATUS [75] Inventor: Christian A. Eff, Louisville, Ky.

[73] Assignee: General Electric Company,

Louisville, Ky.

[22] Filed: Mar. 20, 1974 [21] Appl. No.: 452,847

[52] US. Cl 110/8 R, 110/119, 110/165 A, 55/312 [51] Int. Cl F23j 1/00[58] Field of Search 55/312, 315, 342, 350; 110/8 R, 119,' 165 A [56]References Cited UNITED STATES PATENTS 3,418,788 12/1968 Sugimoto110/165 X 3,608,278 9/1971 Greenspan 110/119 X 3,716,967 2/1973 Doyle,Jr. et a1.. 110/119 X 3,776,149 12/1973 Teich et al 110/8 PrimaryExaminer-Kenneth W. Sprague ABSTRACT A valve and duct means are providedto extract ashladen air from the combustion chamber of an incineratorand direct it to fly ash separators and a finer filter in order thatsmall particles of ash may be separated from the air before the air isexhausted to atmosphere. An alternate path is provided to remove ashremaining in the combustion chamber after an incineration cycle iscompleted. Ash-laden air from the combustion chamber is directed to acyclone separator to remove larger particles of ash from the air. Theair is then sent through the fly ash separators and the finer filter inorder to remove any remaining smaller particles of ash. The air is thenreturned to the combustion chamber where particles of ash remainingtherein are stirred up by the returning air. Electrical circuitry isprovided so that operation of the ash removal apparatus is substantiallyautomatic. A protective circuit prevents operation of the ash-removalapparatus if the temperature in the combustionv chamber is above apredetermined level.

6 Claims, 2 Drawing Figures PATENFED JANZ 8M5 SHEET 2 OF 2 Om TINCINERATOR ASH REMOVAL APPARATUS BACKGROUND OF THE INVENTION 1. Fieldof the Invention The invention is directed to solid waste incineratorsand more particularly to new and improved apparatus for removing ashfrom such incinerators.

2. Description of the Prior Art In modern solid waste incinerators,combustion is very efficient, so that only small amounts of ash are leftin the incinerator after an incineration cycle. A good example of thistype of incinerator is shownin US. Pat. No. 3,742,874, assigned to theassignee of the present invention.

Although this incinerator works well during incineration no provision ismade for removing ash left in the combustion chamber after anincineration cycle is completed. Removal of the remaining ash must bedone manually after an incineration cycleis completed and theincinerator has cooled sufficiently. This is an obviouslytime-consuming, dirty task.

The above-mentioned problems are overcome by the present invention andprovision is made for disposing of even residual ash without thenecessity of the operators manually removing it from the incinerator.Accordingly, it is an object of the invention to provide ash removalapparatus for an incinerator which removes ash substantiallyautomatically, so that the time and effort required of the operator iskept to a minimum.

It is another object of the invention to provide ash removal apparatuswhich removes smaller particles from flue gases during incineration andwhich removes both smaller and larger particles from the combustionchamber after an incineration cycle is completed.

It is a further object of the invention to provide ash removal apparatusincluding a protective device so that ash removal after incineration maybe accomplished only when the combustion chamber is below apredetermined temperature in order to minimize the risk of a fire.

SUMMARY OF THE INVENTION In carrying out the invention, in one formthereof, an incinerator is provided wherein particles of ash are removedfrom a combustion chamber after an incineration cycle is completed. Avalve and duct means are provided to extract ash-laden air from thecombustion chamber and direct it to a first ash separator in order thatlarger particles of ash may be separated from the air. The air is thensent through fly ash separators to remove smaller particles of ashbefore being returned to the combustion chamber where the returning airstirs up any remaining particles. Baffles are provided to selectivelydivert the air flow as required. Electrical circuitry is provided sothat operation of the ash removal. apparatus is substantially automatic.The danger of a fire occurring in the separators is minimized by a pro--tective circuit which prevents operation of the ash removal apparatus ifthe temperature in the combustion chamber is above a predeterminedlevel.

DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENTReferring to FIG. I, there is shown a combustion chamber 12 of anincinerator. An agitator 14 is provided to stir the combustible materialand to break up any carbonized residue which may form in the lowerportion of the combustion chamber. Agitator I4 is driven by shaft I5 ofamotor 147 (shown schematically in FIG. 2). Combustion chamber 12 andagitator 14 operate in the manner described in U.S. Pat. No. 3,742,874.

During an incineration cycle. gases containing smoke and ash particlesare generated. These gases exit combustion chamber 12- through openingI6 and are carried away as flue gases by duct 18, which duct iscomprised of sections 18a and 18b.

A diverting means in the form of movable baffle 20 is disposed withinduct 18. Baffle 20 may occupy a first position, as shown by solid lines,in which it blocks duct 18a. Baffle 20 may be rotated to a secondposition, shown by dotted lines, in which duct 18 is unob structed. Inthis latter position, flue gases evolving from combustion chamber 12 maybe carried directly to fly ash separators 22.

Fly ash separators 22 comprise two cyclone separators 24 and 26 inseries and a finer filter 28 downstream of cyclone separator 26. Portion18b of duct 18 is connected to cyclone separator 24 for conducting fluegases to separator 24 during incineration. Separator 24 includes aremovable container 30, such as a quart jar, for receiving the ashseparated from the flue gases by separator 24. Duct 32 is provided toconnect cyclone separator 24 to cyclone separator 26. Cyclone separa tor26-acts on the flue gases in the same manner as cyclone separator 24,and more fly ash particles are collected in removable container 31,which container may be identical to container 30.

Separator 26 is connected 'to finer filter 28 by duct 34. The purpose offiner filter 28 is to collect whatever fly ash particles remain afterthe ash-laden air has passed through cyclone separators 24 and 26. Forcollecting the ash particles, filter 28 includes a filtering element 39arranged within duct 40. Filtering element 39 is typically a vacuumcleaner. bag.

In order to cool the flue gases before they enter the filter 28, a duct36 is provided for admitting cooler outside air. Duct 36 is connected toan intermediate portion of duct 34. A movable baffle 38 is provided atthe end of the duct 36. Baffle 38 is movable from the position shown inFIG. 1 to an open position in which cooling air is admitted through duct36 during incineration.

In order to draw air through the separators, an exhaust blower or fan 42is connected to duct 40. The blower may be of any conventional type andmay be driven by any suitable driving means. such as a motor indicatedat in FIG. 2. A duct 44 is connected to the exhaust side of blower 42for conducting gases to the atmosphere during incineration. Duct 44 isarranged for communication with a duct 48. Duct '48 is connected to thelower portion of combustion chamber 12 so that air passing therethroughstirs any ash remaining in the combustion chamber.

A movable baffle 46 is placed at the junction of duct 44 and 48. Baffle46 may be placed selectively in a horizontal position, as shown bydotted lines, where it blocks communication with duct 48 duringincineration and causes exhaust gases from duct 44 to pass to atmosphereor in a vertical or intermediate position, represented by solid lines,whereby all or a portion of the gases are directed from duct 44 throughduct 48 to the combustion chamber 12 during ash removal.

Baffles 20, 38 and 46 may be actuated either by a mechanical linkageoperating from ash valve 51 or by interconnected electrical componentssuch as solenoids. Since any suitable mechanical or electricalinterconnections may be employed, the interconnector is illustrated onlyby dotted lines in FIG. 1.

To effect removal of remaining ash from combustion chamber 12, analternate path is provided to the separators. This path includes a duct50 connecting combustion chamber 12 to a cyclone separator 52 which isof a type suitable for handling larger ash particles as opposed to flyash. Separator 52 includes a large disposable paper bag 53 secured by aclamp 54 mounted on frame 55. Virtually all of the larger ash particlesamounting to about 95 percent of the total ash are removed by cycloneseparator 52. A separator throat 56, which is an integral part ofseparator 52, connects separator 52 to portion 18b of duct 18 fordischarging gases from separator 52 to separator 24. When this alternatepath is employed, baffle is in the solid line position shown in FIG. 1.

In order to permit the path through duct 50 to be selectively opened orclosed, the valve 51 is provided. In the solid line portion shown inFIG. 1, valve 51 opens duct 50 providing communication between ductportion 50a and duct portion 501;. When valve 51 is in the dotted lineposition, duct 50 is blocked. Valve 51 is connected by suitable linkages(shown as dotted lines) with baffles 20, 38 and 46 so that the baffles20, 38 and 46 occupy their solid line positions when valve 51 is in itssolid line position and occupy their dotted line positions when valve 51is in its dotted line position.

A circuit diagram according to the invention is shown in FIG. 2. Manyparts of this circuit are not part of the present invention but aredescribed in US Pat. No. 3,742,874. Therefore, the description of thecircuit diagram shown in FIG. 2 will be limited primarily to those partswhich are pertinent to controlling the ash removal apparatus of thepresent invention. It should be understood that applicant has modifiedand improved the electrical system of the referenced patent in order toautomatically and safely operate his ash removal apparatus.

Since container 53 is typically a paper bag, ash particles depositedtherein conceivably could cause a fire if the ash particles were hotenough. It is important, therefore, that the separator 52 be bypassed byair flowing from the combustion chamber 12, not only during theincineration cycle but also at any time the temperature in thecombustion chamber exceeds a predetermined level. It has been determinedthat this level should be no higher than about 140F to insure that theash particles cannot cause a tire in the separator 52. This control ofairflow including the control of other components, such as agitator 14and blower 42, is accomplished by the interrelationship of elements andthe circuitry shown in FIG. 2.

Electrical power is provided by a voltage source comprising a pairofline wires L 1 and L2 having a grounded neutral connector Ntherebetween. Valve 51 (see FIG. 1) is arranged to engage a switch 60when the valve is in the solid line position shown in FIG. 1. Referringnow to FIG. 2, switch 60 includes switch elements 62,

63 and 64, the first switch element being biased to a normally openposition and the latter two switch elements being biased to a normallyclosed position.

The circuit further comprises an interlock thermostat 125 which includesnormally closed contacts 131 and normally open contacts 141. When thetemperature in the combustion chamber is below I40F, the contacts 131and 141 occupy the normal position shown in FIG. 2. During the ashremoval operation, a circuit is provided for the motors and 147 of theblower and agitator, respectively, through the switch element 62 and thecontacts 131. The interlock thermostat 125, by effecting opening of thecontacts 131 if the temperature goes above the predetermined maximumlevel of about 140F, precludes operation of the blower and agitator andthe passage of ash into the bag 53 of the separator 52 under suchconditions.

During the incinerating operation, the valve 51 is in the dotted lineposition shown in FIG. 1. Baffles 20, 38 and 46 also occupy the dottedline positions shown in FIG. 1. Under these circumstances heatingelements 44 and 97 in the incinerator are energized and, when theincinerator reaches a temperature above 140F, interlock thermostatshifts the contacts 131 and 141 to their open and closed positions,respectively. This completes a circuit for the blower motor 80 andagitator motor 147 through closed contacts 141 and switch element 63from line L1 to neutral line N.

With the blower motor in operation, air is drawn from the combustionchamber through duct 18 past the baffle 20 in its dotted line positioninto separator 24, bypassing separator 52. The air then flows throughseparators 24 and 26 where fly ash is removed and then through duct 34into finer filter 28. Ash removed in separators 24 and 26 is deposited.in containers 30 and 31. Still finer particles removed in separator 28are deposited in bag 39.

After leaving the separator 28, the air passes through duct 40 to theblower 42. Air discharged from the blower passes through duct 44 pastthe baffle 46 in its dotted line position to atmosphere.

A door interlock is provided during incineration. An access door (notshown) provides access to the combustion chamber for the deposition ofwaste material. In order to prevent opening of the access door duringincineration, an interlock circuit including locking bolt 164, solenoid129, and contact switch serves to lock the access door when thetemperature in the combustion chamber is greater than about F. When thedoor is closed, interlock switches 132 and 133 are closed. It is seenthat this permits energization of the rest of the circuitry.Additionally, the door interlock circuit is connected through interlockthermostat 125. Since incineration, not ash removal, is desired, switchelements 62, 63 and 64 are in that position shown in FIG. 2. Therefore,a circuit including indicator light 136 is completed when normallyclosed contacts 131 are closed, that is, at a temperature below 140F.Similarly, a circuit including indicator light 137 is completed whennormally open contacts 141 are closed, that is, at a temperature above140F.

Solenoid 129 engages locking bolt 164 when solenoid 129 is de-energized.After an incineration cycle is complete and the incinerator has cooledbelow 140F, the access door may be opened by momentarily pushingnormally open contact switch 130 and thus energizing solenoid 129 torelease locking bolt 164 since a circuit to ground is completed throughnormally closed contacts 131. When another incineration cycle isstarted, normally closed contacts 131 open after reaching 140F, thecircuit containing solenoid 129 is opened, and solenoid 129 cannot beenergized to open locking bolt 164.

A similar procedure occurs during ash removal. However, since the doorremains locked even after the incinerator cools, and since there is noneed to open the door to effect ash removal, it is likely that contactswitch 130 will not be pushed to open the door.

Operation To start the ash removal cycle, valve 51 is opened, that is,moved to the solid line position shown in FIG. 1, so that the duct 50bis open to the passage of ashladen air from the combustion chamber.Simultaneously, baffles 20, 38 and 46 are moved to the solid linepositions shown in FIG. 1.

With the valve 51 in its open position, it engages switch 60. As shownin FIG. 2, when the switch 60 is engaged by the valve 51, the switch ismoved downwardly to close switch element 62 and simultaneously openswitch elements 63 and 64. Under these circumstances, and assuming thatthe temperature in the combustion chamber is below 140F, a circuit forthe blower motor 80 and agitator motor 147 is completed from the line Llthrough switch element 62 and normally closed contacts 131 to neutralline N. Ash-laden air is then drawn from the combustion chamber 12through duct 50 to separator 52 and subsequently through fly ashseparators 24 and 26 and finer filter 28.

Since the baffle 46 is in the open or solid line shown in FIG. 1, airdischarged from the blower 42 is directed through duct 44 and duct 48 tothe bottom of the combustion chamber 12 where it assists in stirring theash to facilitate removal thereof. Larger ash particles are deposited inthe bag 53 of the separator 52 and the smaller particles, or fly ash,are deposited in the containers 30 and 31 of the separators 24 and 26,respectively. The finer filter 28 effects removal of any remaining finerparticles, which are collected in the bag 39.

Should the temperature in the combustion chamber rise above 140F at anytime during the ash removal operation, interlock thermostat 125 effectsopening of contacts 131, interrupting the circuit to the motors 80 and147, locking the access door in a closed position, and discontinuing theash removal operation until such time as the temperature again dropsbelow 140F, at which time contacts 131 again return to their normallyclosed position.

While a specific embodiment of the invention has been described, it willbe obvious to those skilled in the art that changes and modificationsmay be made without departing from the invention. It is thereforeintended in the appended claims to cover all such changes andmodifications that fall within the true spirit and scope of theinvention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. Ash removal apparatus for an incinerator including a combustionchamber comprising:

a. a blower for providing air flow for the incinerator;

b. first means for selectively directing air from the combustion chamberto said blower through a first path during ash removal operation andthrough a second path during incineration;

c. said first path directing air from said combustion chamber through afirst separating means for removing larger ash particles and thenthrough a second separating means for removing smaller ash particles;

d. said second path bypassing said first separating means and directingair from said combustion chamber directly through said second separatingmeans; and

e. second means for selectively directing air discharged from saidblower through a third path to said combustion chamber during ashremoval operation and through a fourth path to atmosphere duringincineration.

2. The ash removal apparatus recited in claim 1 wherein:

J a. said first means includes a valve positioned adjacent saidcombustion chamber and movable between a first position permitting airflow through said first path and a second position blocking air flowthrough said first path; and

b. said first means further includes a baffle movable simultaneouslywith said valve for blocking said second path when said valve is in saidfirst position.

3. The ash removal apparatus recited in claim 1 wherein:

. a. said second means includes a first duct connecting said blower toatmosphere;

b. a second duct connecting said first duct to said combustion chamber;and

c. a baffle positioned at the junction of said first and second ductsfor selectively directing air from said first duct to atmosphere orthrough said second duct to said combustion chamber.

4. The ash removal apparatus recited in claim 1 wherein said secondseparating means includes a plurality of serially connected separatorssuitable for removing fly ash and a third separator connecting betweensaid plurality of separators and said blower for removing finer ashparticles.

5. The ash removal apparatus recited in claim 4 and further including aduct connecting said plurality of said separators and said thirdseparator and means for introducing air from the atmosphere through saidduct to maintain the temperature in said third separator below apredetermined level.

6. The ash removal apparatus of claim 2 wherein said first means furtherincludes a valve and electrical circuitry means associated therewith forsimultaneously diverting ash-laden air to said first separating meansand energizing said exhaust blower, said electrical cir cuitry meansresponsive to the temperature within said combustion chamber so thatpower to said exhaust blower is interrupted if the temperature withinsaid combustion chamber exceeds a predetermined value.

1. Ash removal apparatus for an incinerator including a combustionchamber comprising: a. a blower for providing air flow for theincinerator; b. first means for selectively directing air from thecombustion chamber to said blower through a first path during ashremoval operation and through a second path during incineration; c. saidfirst path directing air from said combustion chamber through a firstseparating means for removing larger ash particles and then through asecond separating means for removing smaller ash particles; d. saidsecond path bypassing said first separating means and directing air fromsaid combustion chamber directly through said second separating means;and e. second means for selectively directing air discharged from saidblower through a third path to said combustion chamber during ashremoval operation and through a fourth path to atmosphere duringincineration.
 2. The ash removal apparatus recited in claim 1 wherein:a. said first means includes a valve positioned adjacent said combustionchamber and movable between a first position permitting air flow throughsaid first path and a second position blocking air flow through saidfirst path; and b. said first means further includes a baffle movablesimultaneously with said valve for blocking said second path when saidvalve is in said first position.
 3. The ash removal apparatus recited inclaim 1 wherein: a. said second means includes a first duct connectingsaid blower to atmosphere; b. a second duct connecting said first ductto said combustion chamber; and c. a baffle positioned at the junctionof said first and second ducts for selectively directing air From saidfirst duct to atmosphere or through said second duct to said combustionchamber.
 4. The ash removal apparatus recited in claim 1 wherein saidsecond separating means includes a plurality of serially connectedseparators suitable for removing fly ash and a third separatorconnecting between said plurality of separators and said blower forremoving finer ash particles.
 5. The ash removal apparatus recited inclaim 4 and further including a duct connecting said plurality of saidseparators and said third separator and means for introducing air fromthe atmosphere through said duct to maintain the temperature in saidthird separator below a predetermined level.
 6. The ash removalapparatus of claim 2 wherein said first means further includes a valveand electrical circuitry means associated therewith for simultaneouslydiverting ash-laden air to said first separating means and energizingsaid exhaust blower, said electrical circuitry means responsive to thetemperature within said combustion chamber so that power to said exhaustblower is interrupted if the temperature within said combustion chamberexceeds a predetermined value.